Compressors, Gas Turbines and Jet Engines MCQs

Question 1

1 m of air at atmospheric condition weighs approximately

Accepted Answer

1.3 kg

Answer

0.5 kg

Answer

1.0 kg

Answer

2.2 kg

Question 2

A simple turbojet engine is basically

Accepted Answer

Gas turbine engine equipped with a propulsive nozzle and diffuse

Answer

A propeller system

Answer

Chemical rocket engine

Answer

Ramjet engine

Question 3

The efficiency of a jet engine is higher at

Accepted Answer

High altitudes

Answer

Low speeds

Answer

High speeds

Answer

Low altitudes

Question 4

The degree of reaction in an axial flow compressor is defined as the ratio of static enthalpy rise in the

Accepted Answer

Rotor to static enthalpy rise in the stage

Answer

Rotor to static enthalpy rise in the stator

Answer

Stator to static enthalpy rise in the rotor

Answer

Stator to static enthalpy rise in the stage

Question 5

The performance of air compressor at high altitudes will be ________ as compared to that at sea level.

Accepted Answer

Lower

Answer

Same

Answer

Higher

Answer

None of these

Question 6

Maximum work is done in compressing air when the compression is

Accepted Answer

Adiabatic

Answer

Isothermal

Answer

Polytropic

Answer

None of the above

Question 7

The volumetric efficiency of a compressor falls roughly as follows for every 5°C increase in atmospheric temperature

Accepted Answer

1%

Answer

0.1%

Answer

0.5%

Answer

5%

Question 8

The area of actual indicator diagram on an air compressor as compared to area of ideal indicator diagram is

Accepted Answer

More

Answer

Less

Answer

Same

Answer

More/less depending on compressor capacity

Question 9

In a centrifugal compressor, the highest Mach number leading to shock wave in the fluid flow occurs at

Accepted Answer

Diffuser outlet radius

Answer

Diffuser inlet radius

Answer

Impeller inlet radius

Answer

Impeller outlet radius